The present invention relates generally to a method and an apparatus for manufacturing thin-film photoelectric conversion modules, and relates more particularly to a method and an apparatus for manufacturing thin-film photoelectric conversion modules which are protected on both major surfaces by sandwiching a plurality of thin-film photoelectric conversion elements disposed on a flexible substrate between flexible weatherproof films.
A prior art thin-film photoelectric conversion element in which a rear electrode layer, a photoelectric conversion layer and a transparent electrode layer are disposed, in that order, on a substrate is known from a Japanese patent disclosure No. HEI 5-72113. In this prior art photoelectric conversion element, the rear electrode layer, the photoelectric conversion layer, and the transparent electrode layer are arranged such that the photoelectric conversion element converts light admitted from the transparent electrode layer side into electric power. Further, each layer of this prior art photoelectric conversion element is separated from the adjacent layers by using different patterning methods before a subsequent layer is formed, thereby creating a series-connection structure.
Also known in the prior art is a method of "modularizing" multiple photoelectric conversion elements into one conversion module by electrically connecting the individual conversion elements via connecting conductors and covering both sides of the conversion elements with protective films. In this manner, the photoelectric conversion elements are protected from the influence of ambient moisture and gases. This prior art method is disclosed in the Japanese patent disclosure No. HEI 5-59591.
In the above-described prior art embodiments, connections for modularization are accomplished by using exposed portions on the rear electrode layer and the transparent electrode layer of the substrate. Therefore, the electrode layer must be kept exposed until the bonding process is completed and, as a result, its surface cannot be protected during the bonding process. This drawback leads to, among other things, defects caused by changes in surface properties during the manufacturing process, and a breakdown of the photoelectric conversion elements when the element characteristics are being measured. In addition, if a plastic film used as the flexible substrate is extremely thin, the manufacturing process is further complicated by the need for the fragile film to be handled with extreme care when it is divided into a sub-module size from a film roll.